Pressure balancing spool mixing valve

ABSTRACT

There is herein described a single handle pressure balancing spool valve for mixing user-adjustable hot and cold water flow to a fixture such as a shower or tub and to adjust the rate of mixed water flow. A rotatable disc with hot and cold intake openings and an outlet opening are provided which control the degree of covering on the inlet ports of the valve. Pressure balancing of inlet pressure is provided within the valve by means of a piston-cylinder assembly to compensate for fluctuations in water inlet pressure to avoid scalding of the user.

FIELD OF THE INVENTION

The present invention relates to a cartridge type of pressure-balancingspool valve for use in residential and commercial plumbing applications,particularly for bathtubs and showers. More particularly mixing valvesof this type are employed for balancing water pressure, volume of flowand water temperature.

BACKGROUND OF THE INVENTION

In the plumbing market today, single handle mixing valves are common,especially for use in sinks, tubs and shower installations. Many ofthese valves will mix the flow of hot and cold water to suit the desiresof the user. The more expensive and advanced valves of this type alsoinclude a pressure balancing assembly to prevent a rapid change of watertemperature when either the hot water supply or cold water supplypressure drops. This can cause severe injury due to scalding if notcorrected.

Such pressure drops can occur if another plumbing apparatus, such as adishwasher, faucet, toilet or washing machine is actuated, which canresult in an excessive flow of either hot or cold water. Many types ofpressure balancing components have been incorporated in mixing vales inorder to obviate such problems.

There is a need in the art for a cartridge type mixing valve whichprovides pressure balancing between the hot and cold water supplies andwhich also provides a full adjustment of the water temperature from fullcold to about 115° F. in a compact easily assembled mixing valve housingwhich has provision for easy replacement of parts when needed.

SUMMARY AND OBJECTS OF THE INVENTION

In accordance with a preferred embodiment of our invention, a pressurebalancing mixing valve is provided which incorporates a plasticthree-piece pressure balancing spool housing component which is adaptedto be attached to and integrated with a standard 35 mm ceramic discsingle control valve cartridge.

It is a primary object of our invention to provide a pressure balancedmixing valve which includes a group of components, each havingindividual functions, which are pre-assembled and integrated to form avalve assembly which can be easily inserted and removed as a unit fromthe body of a tap.

This object is achieved by superimposing and assembling the ceramic discmixer valve and pressure balancer or regulator as a single unit forcorrect positioning within the plumbing fixture or tap.

It is a further object of the invention to provide a novel pressurebalance cartridge valve assembly that can be easily removed from aplumbing system for replacement or repair of component parts.

Another object of the invention is to provide a pressure balancing valveassembly that is relatively inexpensive to manufacture and which isdurable and reliable in use and which is designed to prevent injury dueto scalding of the user due to fluctuations in water pressure in theplumbing system.

Further objects of the invention will become apparent upon a carefulreading of the appended specification, claims and drawings, wherein likereference characters refer to the same elements which appear in theseveral views.

DESCRIPTION OF RELATED ART

It has been previously suggested in the prior art to incorporatepressure balancing and mixing of hot and cold water in a single controlvalve. An example of such a valve is shown in Otelli, U.S. Pat. No.6,732,754.

Another example of a pressure balancing mixing-valve is shown in Martyet al., U.S. Pat. No. 5,35,906

Lin et al., U.S. Pat. No. 6,176,250, is directed to a pressure balancesub-assembly for proportionally mixing hot and cold water.

In these known constructions, the pressure balance valve portion hasbeen subject to erratic operation, breakage and fouling, all of whichhave been obviated in our new valve construction.

In addition to the above, the assemblage of the main components of theprior art valves has been complicated and time-consuming resulting inadditional manufacturing costs.

SUMMARY OF THE INVENTION

Consistent and consonant with the present invention, a pressurebalancing spool mixing valve is disclosed which incorporates a generallyconventional 35 mm ceramic disc single control cartridge with a threepiece pressure balance housing design which attaches to the disccartridge assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects of our invention will be appreciated andunderstood by those skilled in the art from the detailed description ofthe preferred embodiment of the invention and from the followingdrawings in which:

FIG. 1 is a bottom right perspective view of a pressure balancing spoolpressure valve constructed according to our invention;

FIG. 2 is a top right perspective view opposite of the view in FIG. 1;

FIG. 3 is a cross-sectional view of the top operating portion of thevalve showing a typical installation with an operating handle in a bathor shower environment;

FIG. 4 is an exploded perspective of the major operating components ofthe valve including the pressure balancing cylinder and piston and thetwo side housings;

FIG. 5 is an exploded perspective showing the assembly of the fixed andmovable discs for control of hot and cold water flow;

FIG. 6 is a cross-section of the entire valve assembly taken from theleft side along line 6-6 of FIG. 1 and showing the valve in the fullyclosed position wherein no flow to the outlet takes place;

FIG. 7 is a cross-section taken along line 7-7 of FIG. 6 showing theinlets and outlet in the disc assembly when the valve is closed;

FIG. 8 is a cross-section of the entire valve assembly similar to FIG. 6showing the valve in the fully open position wherein both hot and coldwater may flow to the valve outlet.

FIG. 9 is a cross-section taken along Line 9-9 of FIG. 8 showing theinlets and outlet in the disc assembly when the valve is open.

FIG. 10 is a cross-section similar to FIG. 9 and showing the valve inthe position for maximum hot water flow.

FIG. 11 is a cross-section similar to FIG. 9, but showing the valve inthe position for maximum cold water flow.

FIG. 12 is a cross-section of the valve in FIG. 6 taken along the line12-12 thereof.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

With reference to the drawings wherein like reference charactersdesignate like or corresponding elements throughout the several views,it will be seen that the invention relates to a pressure balancing spoolmixing valve shown generally at 10. The body of the valve itself ispreferably formed from any well known plastic material.

In the preferred embodiment, the valve 10 is an assembly of two majorcomponents, a pressure balancing sub-assembly 11 and a conventionalceramic disc single control cartridge sub-assembly 12, which ispreferably of a standard 35 mm outside diameter in order to fit withinexisting home and commercial plumbing fixtures.

The two sub-assemblies 11 and 12 are retained and held together by a tab13 and slot 14 connection or any other suitable means known to thoseskilled in the art.

As can be seen in FIG. 3, the cartridge valve assembly extends throughan opening in a bathroom wall W, for example. The operating spindle 15of the valve is connected to a conventional shower handle 16 by means ofa screw 17 or other fastener which is received in a threaded bore 18 inthe end of the spindle 15. A trim plate or escutcheon T conceals andcovers the assembly.

Spindle 15 is secured by means of a metal pin 19 to a rotatable plasticdisc 20, whereby rotation of the handle 16 will result in the rotationof the spindle 15 about its longitudinal axis, resulting in rotation ofthe disc 20 for the purpose of control of water temperature at theoutlet of the valve. The spindle can also be pivoted about the pin 19 inorder to control the rate of flow or pressure of the water at the valveoutlet.

The rotatable disc 20 and the operating spindle are received within theplastic cartridge housing 21 as noted in FIG. 4 of the drawings. Aplastic locating ring 22 is fixed over the rotatable disc and attachesto the top of the housing 21.

The end of the operating spindle 15 internal of the valve assembly isprovided with a finger or foot 23 engageable within a recess 24 inceramic plate or holder 25. This plate has depending lugs 26 which areengageable with recesses 27 formed in moveable disc 28. Formed into thebottom surface of disc 28 is a keyhole recess or depression 29 whichcontrols the outflow of water through the valve as described furtherherein.

Pivotal movement of spindle 15 about the pin 19 serves to move ceramicplate 25 and the disc 28 to which it is attached and which includes thekeyhole recess 29.

The bottom portion of our new valve constituting the pressure balancingassembly 11 includes a plastic molded housing 30. Three openings areformed in the bottom of the housing; the hot water inlet 31, the coldwater inlet 32, and the mixed water outlet 33. Silicon gaskets 34surround the hot and cold water inlets. An o-ring gasket 35 extendsabout the periphery of housing 30 as is conventional in the art.

The top or upper surface of the molded housing 30 is provided with threepreferably circular water openings 36 to correspond with the hot andcold water inlets and the outlet. O-ring gaskets 37 are fitted aboutthese openings

A plurality of upstanding lugs 38 extend from the housing 30 and receivea fixed disc 39 by virtue of interengagement with complementary recesses38 a and which disc is provided with a pair of arcuate openings 40 and41 and a larger generally circular opening 42.

It may be seen from an inspection of FIGS. 4, 5, 7, 9, 10 and 11 thatrotation of the shower handle 16 and its connected operating spindle 15will result in the rotation of the moveable disc 28 with respect to thefixed disc 39. Such rotation opens and closes the passageways for thehot and cold water which communicate with the keyhole recess 29 for thepurpose of mixing the appropriate proportion of hot and cold water tothe outlet 33.

Pressure balancing of the water is accomplished by the inclusion in theplastic housing 21 of pressure balance sub-assembly shown at the bottomof FIG. 4. This includes a pair of oppositely directed side housings 43and 44, each having a cylindrical opening 45 to receive a stainlesssteel cylinder 46 in which freely slides a stainless steel piston 47.The side housings surround and seal the anti-fouling treated stainlesssteel cylinder and piston.

The stainless steel piston acts to compensate the flow due to waterpressure fluctuations while each side housing maintains the hot and coldwater supplies separated at all times.

The pressure balancing assembly 11 is snap fitted to the ceramic singlecontrol cartridge 12 as shown in FIGS. 1 and 2.

Our invention is not limited to the above-noted embodiment as variousmodifications can be readily made by those skilled in the art. Suchchanges in form and detail may be made without a departure from thescope and spirit of our present invention.

1. A single control pressure balancing spool mixing valve comprising: anupper single control cartridge and a lower pressure control housing,said cartridge and housing being joined together axially; said controlcartridge including an operating spindle extending axially therein andbeing rotatable about its longitudinal axis; a pivot pin extendingthrough said spindle intermediate the ends of the spindle, whereby saidspindle can pivot about said pin; said pressure control housing having ahot water inlet, a cold water inlet, and a mixed water outlet; moveabledisc means adopted to proportion the amount of hot and cold waterflowing through the valve to said mixed water outlet, said means beingoperatively connected to one end of said spindle for rotation therewith;said moveable disc having a recess on one surface thereof to receivesaid one end of said spindle, whereby movement of said spindle aboutsaid pin will cause lateral movement of said moveable disc; means onsaid moveable disc to control the volume of mixed water flow as a resultof the pivoting of the spindle and the moveable disc; pressure balancemeans within said housing and in communicate with both the hot and coldwater inlets to sense and compensate for any fluctuation in the pressureof either the hot or cold water.
 2. The valve as defined in claim 1,wherein said pressure balance means comprises a pair of oppositelyfacing side housings, each having a generally cylindrical recess, acylinder received within said recesses, and a piston slidable withinsaid cylinder, one of said side housings being in fluid communicationwith inflowing hot water and the other being in communication withinflowing cold water.
 3. The valve as defined in claim 2, wherein thecylinder and the piston are formed on stainless steel.
 4. The valve asdefined in claim 1, and further including an operating handle secured tothe other end of said spindle for rotating and pivoting the same tocontrol the temperature and flow rate of water to said outlet.
 5. Thevalve as defined in claim 1, wherein said moveable disc means isrotatable upon rotation of said spindle.
 6. The valve as defined inclaim 5, and further including a keyhole-shaped recess on its lowerface, and a fixed disc having openings in communication with the hot andcold water inlets and said outlet, said moveable disc upon rotation withrespect to said fixed disc varies the proportional amount of hot andcold water flowing to said outlet.
 7. The valve as defined in claim 5,wherein said openings in said fixed disc for the hot and cold water arearcuate in shape.
 8. The valve as defined in claim 7, wherein saidopening in said fixed disc for the mixed water outlet is generallycircular in shape.